Question: Why is water considered a polar molecule? Answer: Water is a polar molecule because the hydrogen and oxygen polar bonds in a “V” shape. The oxygen end contains the negative pole of the molecule and the end with the two hydrogen is the positive pole. -megan 2. For each of the below listed properties of water, briefly define the property and then explain how water’s polar nature and polar covalent bonds contribute to the water special property. Include an example in nature of each property also. a. Cohesion: the water is able to stick to itself Example: Cohesion helps water molecules stick together and get water from tree roots to tree leaves. Because water is polar, hydrogen bonds can be formed between water molecules and allow the water molecules to “pull” one another up. b. Adhesion: allows water to stick to other things Because water is polar, it can stick to other polar molecules. Example: Adhesion is the reason dew sticks to plants and other things. c. Surface tension: the attraction that surface molecules on a liquid have for one another. Hydrogen bonds form between water molecules and allow things to move on water. Example: Surface tension is the reason things can float on water. d. High specific heat: the amount of energy required to raise the temperature of water. Water has a high specific heat because of hydrogen bonding. Hydrogen bonding is a strong force and a major amount of energy is needed to break the hydrogen bonding. Therefore, more energy is needed to raise the temperature. e. Evaporative cooling: Molecules entering the vapor phase take their heat with them and lower the temperature of the object. Water molecules take a lot of heat to enter the vapor phase because of its high specific heat and strong hydrogen bonds.
-kate
3. What is special about water (in different phases) and density? How is this unusual property important to life? As water changes to a solid, unlike other molecules, it becomes less dense. This is important to life because if ice were more dense, it would kill sea life by forming from the bottom to the top, which is where fish inhabit.
-CJ
3. What is special about water (in different phases) and density? How is this usual property important to life? Water can freeze up and the particles become solid because of H-bonds. When water is solids they spread out and expend. Therefore, ice isn’t heavy. H-bonds form a crystal, like the example below. Water can also become a liquid; the particles are loose and spread out. They can stick to things, like for example h-bonding between H20 molecules is cohesion. Cohesion helps water to stick like drinking straw. Water can become a gas. This is when you boil or seam water. The particles intends to be bouncing and everywhere in the boiling water. They move really fast.
-Tina
4. Define the following terms: a. Solute- a dissolved substance because of the localized partial positive charge on the hydrogen atoms and partial negative charge on the oxygen atom causing each water molecule to attract and surround the anions and cations b. Solvent- capable of dissolving many substances, particularly those that are polar or ionic, because of the polarity of water molecules -ashley 8. What is a buffer and write and explain the carbonic acid buffer system in human blood? A substance or combination of substances that resists changes in pH when an acid or base is added is a buffer. In the carbonic acid buffer system in human blood, carbon dioxide enters the blood and reacts with the water to form carbonic acid, a weak acid that dissociates to yield a hydrogen ion and a bicarbonate ion. Weak acids and bases do not ionize completely, only a fraction of the molecules are ionized. -ashley
What is a buffer and write and explain the carbonic acid buffer system in human blood? A buffer is a solution usually containing a weak acid and its conjugate weak base of such a composition that the pH is held constant within a certain range. In the human blood, a carbonic acid buffer system takes place. Acids (H+) released into the blood by the body cells tend to lower the pH of the blood and cause it to be acidic. Small changes in H+ ions are buffered by the bicarbonate buffering system and blood pH will be corrected on a short term by expelling the excess ions as C02 from the lungs. Carbon dioxide enters the blood, it reacts with water to form a carbonic acid. On a longer time scale, ion levels are maintained by the kidneys and digestive system. In some ways a high pH (insufficient H+) is harder to correct for. While changing the rate of respiration will alter pH, stopping breathing to bring down pH also decreases the availability of oxygen.
-brandon
Answer: Water is a polar molecule because the hydrogen and oxygen polar bonds in a “V” shape. The oxygen end contains the negative pole of the molecule and the end with the two hydrogen is the positive pole.
-megan
2. For each of the below listed properties of water, briefly define the property and then explain how water’s polar nature and polar covalent bonds contribute to the water special property. Include an example in nature of each property also.
a. Cohesion: the water is able to stick to itself Example: Cohesion helps water molecules stick together and get water from tree roots to tree leaves. Because water is polar, hydrogen bonds can be formed between water molecules and allow the water molecules to “pull” one another up.
b. Adhesion: allows water to stick to other things Because water is polar, it can stick to other polar molecules. Example: Adhesion is the reason dew sticks to plants and other things.
c. Surface tension: the attraction that surface molecules on a liquid have for one another. Hydrogen bonds form between water molecules and allow things to move on water. Example: Surface tension is the reason things can float on water.
d. High specific heat: the amount of energy required to raise the temperature of water. Water has a high specific heat because of hydrogen bonding. Hydrogen bonding is a strong force and a major amount of energy is needed to break the hydrogen bonding. Therefore, more energy is needed to raise the temperature.
e. Evaporative cooling: Molecules entering the vapor phase take their heat with them and lower the temperature of the object. Water molecules take a lot of heat to enter the vapor phase because of its high specific heat and strong hydrogen bonds.
-kate
3. What is special about water (in different phases) and density? How is this unusual property important to life?
As water changes to a solid, unlike other molecules, it becomes less dense. This is important to life because if ice were more dense, it would kill sea life by forming from the bottom to the top, which is where fish inhabit.
-CJ
3. What is special about water (in different phases) and density? How is this usual property important to life?
Water can freeze up and the particles become solid because of H-bonds. When water is solids they spread out and expend. Therefore, ice isn’t heavy. H-bonds form a crystal, like the example below.
Water can also become a liquid; the particles are loose and spread out. They can stick to things, like for example h-bonding between H20 molecules is cohesion. Cohesion helps water to stick like drinking straw.
Water can become a gas. This is when you boil or seam water. The particles intends to be bouncing and everywhere in the boiling water. They move really fast.
-Tina
4. Define the following terms:
a. Solute- a dissolved substance because of the localized partial positive charge on the hydrogen atoms and partial negative charge on the oxygen atom causing each water molecule to attract and surround the anions and cations
b. Solvent- capable of dissolving many substances, particularly those that are polar or ionic, because of the polarity of water molecules
-ashley
8. What is a buffer and write and explain the carbonic acid buffer system in human blood?
A substance or combination of substances that resists changes in pH when an acid or base is added is a buffer. In the carbonic acid buffer system in human blood, carbon dioxide enters the blood and reacts with the water to form carbonic acid, a weak acid that dissociates to yield a hydrogen ion and a bicarbonate ion. Weak acids and bases do not ionize completely, only a fraction of the molecules are ionized.
-ashley
What is a buffer and write and explain the carbonic acid buffer system in human blood?
A buffer is a solution usually containing a weak acid and its conjugate weak base of such a composition that the pH is held constant within a certain range. In the human blood, a carbonic acid buffer system takes place. Acids (H+) released into the blood by the body cells tend to lower the pH of the blood and cause it to be acidic. Small changes in H+ ions are buffered by the bicarbonate buffering system and blood pH will be corrected on a short term by expelling the excess ions as C02 from the lungs. Carbon dioxide enters the blood, it reacts with water to form a carbonic acid. On a longer time scale, ion levels are maintained by the kidneys and digestive system. In some ways a high pH (insufficient H+) is harder to correct for. While changing the rate of respiration will alter pH, stopping breathing to bring down pH also decreases the availability of oxygen.
-brandon